Dispersion effects in elastic electron scattering from C12
Abstract
An experiment to investigate to what extent dispersion effects contribute to the reaction mechanism of elastic electron scattering from C12 is described. The study of the elastic C12 cross sections in the onephoton exchange formalism demonstrates unambigously the existence of a formfactor energy dependence of 8 percent in the first diffraction minimum between an incident energy of 240 and 430 MeV. A sufficiently large momentumtransfer range was covered to show that also outside the diffraction minimum the onephoton exchange treatment fails to describe the experimental data. Here, discrepancies of 3 percent are observed between the date sets at the two incident energies. However, the observed energy dependence in the diffraction minimum has a different sign than outside the minimum. In the diffraction minimum the dispersive contributions increase with energy. The observed discrepancies in the onephoton exhcange analysis do not allow to neglect dispersive contributions in highprecision elastic electronscattering data. Their effect on the groundstate charge distribution is shown to be comparable to that of experimental uncertainties in the absolute normalization and in the momentun scale.
 Publication:

Ph.D. Thesis
 Pub Date:
 1988
 Bibcode:
 1988PhDT.........2O
 Keywords:

 Carbon 12;
 Elastic Scattering;
 Electron Scattering;
 Formalism;
 Nuclear Reactions;
 Scattering Cross Sections;
 Statistical Analysis;
 Atomic and Molecular Physics